Technical Field
The disclosed embodiments relate to a conductive substrate and a touch display device.
Related Art
With the progress of technologies, a touch input function has been widely applied to various electronic products. For a display device capable of the touch function, a user can conduct many functions by directly touching or clicking the screen thereof so that the user's operation can be simplified a lot.
According to the structure type, the touch display device can be divided into an out cell type and an in cell type. For the out cell type, a substrate with a touch function is added to a display panel so that the whole structure has at least three substrates. For the in cell type, it can be further divided into two kinds, in one of which the touch conductive patterns are embedded in the liquid crystal (LC) pixels, and in the other the touch conductive patterns are embedded between the color filter (CF) substrate and the polarizer. The latter kind is also called the on cell type. For the in cell type, the touch function is integrated into the display panel so that the whole structure just has two substrates, i.e. the two substrates of the display panel. Because the product of the in cell type can be made thinner and lighter, and can be made by less processes (e.g. the alignment process is omitted) and the less cost, the touch display device of the in cell type will become the mainstream product in the future.
FIG. 1 is a schematic diagram of a conventional touch display device 1 of the on cell type. The touch display device 1 includes a first substrate 11, a second substrate 12, a liquid crystal layer 13, and a signal processing module 14. The first substrate 11 has a plurality of first conductive patterns 111 which are sequentially disposed on the first substrate 11. The second substrate 12 is disposed opposite to the first substrate 11, and has a plurality of second conductive patterns 121 which are sequentially disposed on the second substrate 12. The first and second conductive patterns 111 and 121 all function as electrodes. The liquid crystal layer 13 is disposed between the first and second substrates 11 and 12. The first conductive patterns 111 and the second conductive patterns 121 are electrically connected to the signal processing module 14 through conductive wires, respectively, for transmitting the signal about capacitance variation caused by the user's touch or click. The signal processing module 14 generates a coordinate signal representing the touch input by processing the signals from the conductive wires.
However, because the first conductive patterns 111 are disposed apart on the first substrate 11, different transmittances are caused by the thickness difference and refractive index difference between the portion with the first conductive patterns and the portion without the first conductive patterns, and the edge scattering effect. Besides, because each of the first conductive patterns 111 is disposed on the first substrate 11 in the form of a rectangle, moiré interference is easily caused by the first conductive patterns 111 and the pixel structures. Therefore, when the user views the touch display device 1, the edges of the first conductive patterns 111 are easily perceived by the human eyes, thereby affecting the display effectiveness of the touch display device 1.
Therefore, it is an important subject to provide a conductive substrate and a touch display device wherein the edges of the conductive patterns are blurred for enhancing the whole visual effect.